The present invention relates to a metal support matrix for a catalytic reactor for exhaust emission control, in particular for catalytic converters for internal combustion engines.
It is known from EP-A1 245 737 to produce a metal support matrix for a catalytic reactor by layering a plurality of smooth and corrugated metal strips alternately to form one stack, and twisting the ends of this stack around two fixed points. This metal support matrix is inserted into a tubular jacket and connected thereto using techniques wellknown in the art.
The foregoing method has the disadvantage that special or custom-designed forms have to be produced by inserting loose filling pieces. Moreover, it is disadvantageous that twisting thicker sheet metal stacks, which are required to produce larger catalyst diameters, requires exceptionally high forces.
It is also known from DE-U1 89 08 671 to produce metal support matrices from more than two stacks, the individual stacks being folded about a bend line and subsequently twisted jointly. A disadvantage of this procedure is that each individual stack must be folded in a separate work step. Moreover, with this type of production of a metal support matrix, regions unoccupied by the honeycomb remain in the interior of the support matrix, in particular in the center of the support matrix.